I traded some emails with Fireblade and we thought this thread would be useful. What is working for you? What did not? There are no absolutes in audio..so on we go.

I have a pair of Pope/Philips 6v6's that are very nice but the Russian 6v6's are very close and 1/5 th the price. Got 'em on flea bay. These are the tubes the first 50 Mini's shipped with. Thumbs up!

OC2's, my amp came with a pair of Russian SGP16 tubes. I tried some Tungsrams but the Russky's sounded better. YMMV. I bought 10 more on fleabay for less than $20 delivered from the Ukraine. I have never had a problem with Russian sellers.

The new issue Tung Sol 6V6 has been very favorably received...a pair is on the way.

Small signal tubes. I have tried several new production types...just because but there are better NOS tubes for close to the same money. *I* just can't get myself to pay $90 for Chinese tubes like PSvanes....yet. I have a good collection of NOS, too many, and the rare=expensive are not often the best sounding. GE and Tung Sol long plate 12AX7's are nice and not expensive. Tungsram 12AU/X7's are very good too. The Tungsram 12AU7 is less expensive and sounds like a Mullard but with better upper frequencies.

I'm fine..and so is the Mini. I really like this amp! You were correct, there is synergy between the Mini and Heresy's. I like the 12AT7 too. Right now I'm using Hytron 5963's that I have had for ages and they sound excellent.

I have been comparing rectifiers and The JJ EZ81 sounds as good as a Mullard in the Mini. That was a surprise. However, I'll limit the JJ EZ81 to 6V6's. The 6L6 types seem to too much for JJ's.

I do want to try a pair of the reissue Gold Lion 6V6's. The reissue Tung Sols are quite good too.

Very good! I have (too) many amps...I love them all, really, but there is something about the MT that keeps the tubes warm on a regular basis; I forget about my archaic, and honestly quite tiring, modification attempts and just enjoy very good reproduction of music. I absolutely...totally...understand the interest in modification, but after more than twenty years of doing that, just don't see (or better hear!) the need for it in this amplifier. Ok, yes, there has been some mild tube rolling, but everything else is OEM. But wait...there is the headphone jack. The MT is hands down the single best headphone amp I have ever had.

I received a pair of new issue Gold Lion 6V6's that are cryoed and matched. I'm not convinced about the cryo benefits but I do like to buy new production tubes that are tested by the vendor.The Mini does not require matched pairs but matching never hurts. More after 100 hours or so but out of the box they are pretty sweet.

Hey Les! Looking forward to your final impressions on both the Jensen Caps and these new cryoed output tubes, once the combined breaking periods have expired. Also, please report the driver/rectifier combo that better suit those preferred 6V6's in the end. Need to take advantage of that tube-aholic syndrome of yours ...

The caps are settled in and sound good. I just like Jensens with tubes and Klipsch. I would probably have left the caps alone if I had different speakers.

IMHO, 6V6's sound better in my rig with an EZ80 rectifier than with an EZ81. I ran the Valve Art 350B's with an EZ80 and had no problems. However, I prefer 6V6's in this amp. Tungsram and RFT EZ80's are both very good and not expensive.

Regarding input tubes, much depends on the rest of your system so you will have to experiment a bit to find your sweet spot.

I have a pair of Psvane 12AT7's coming. There has been a lot of good things said about them and many prefer Psvanes to revered NOS so...I'll post atfer they arrive and settle in. I don't like to buy used small signal tubes on fleabay unless I know the seller because there is just too much junk being sold.

BTW, be patient with new and NOS small signal tubes in the Mini. The Brimars 12AT7's I told you about took 4 ever and a day to settle in and it was a painful sonic journey. They sound excellent now.

Interesting, Les. I wonder what results have you got rolling different signal tubes so far. Assuming you combined them with the EZ80 rectifiers every time, what signal tubes you've tried were best in the Mini given your conditions?

I still ignore the reasons my M-T came with 6N1P-Ev drivers instead of the traditional 12aU7's. I wonder what would be the difference and why were these picked by Steve in my case. Are there any gain issues involved, as the M-T is quite a highish gain amp?

What were the differences observed when replacing the original JJ rectifyiers with those EZ80's?

Also, interested in learning if rolling drivers alone may improve transparency on some less well recorded selections in my system. These recordings tend to sound somewhat constipated and less 'airy' than well recorded ones. Sound definition is what I would be interested in improving, which explains my current concerns with front-end issues.

What are the kinds of changes you look for or detect while rolling drivers in the Mini? Do you believe tube rolling in general may improve sound in some circumstances or just flavors of it?

Excuse the avalanche of questions :). Thanks for the always valid tips, Les.

It is almost impossible to accurately describe the difference in tubes in writing.

The EZ80's seem to have more body than the JJ EZ81's. I have Mullard and Valvo EZ81's too but to me the EZ80's sound better...in my rig.Different cables and front ends can produce different results. The EZ80's are cheap enough to try and they last a very long time.

Tube rolling will not improve the transparency of a poor recording. A Mullard 12AT7 or Sylvania 12AT7WA may make it more listenable. The Mullard and Sylvania are softer and a bit seductive. I've tried a lot of different tubes and still like the Tungsram 12AU7 and the Brimar 12AT7. I have 12AX7's but they may have too much gain in the Mini. My source is more than 2 volts and that may be the issue. The Russian SG16P voltage regulator sounds different than the American OA2 and is cheap and worth trying. It affects the sound of the input tube. I'm not going to go crazy rolling tubes. I guess I'll try 6N1P's too They are certainly cheap enough.

6V6's? None are bad but the new Tung Sols and Gold Lion are excellent and I am going to stick with them. I got a pair of, not cheap, Pope 6V6's and both of the above are better sounding in the Mini. They also sound better than the Russian black glass 6P6S/6V6. Most of what is said about 6V6 sonics on the net applies to their use in guitar amps not audio.

Your front end may be fine. Some CD's are just so poorly done that nothing can fix them.

I decided to try the 12AT7 Psvanes...even though I said I wouldn't. Fingers crossed. I think I'll eventually try the JJ and Gold Lion 12AT7.Has anone used these in the Mini?

You will notice a difference with the rectifiers. They are inexpensive and last a long time.

The JJ 6V6's are not bad either. They are in the amp now. It is great to have decent new production power tubes. The prices on some NOS 6V6 may be high because of rarity and in certain guitar amps they may be the ticket. In the Mini they may not be the cats meow. There is a guy in Hawaii that builds a 6V6 amp and he loves the new production Tung Sols. I am going to stay with new production power tubes and see which small signal tube and rectifers work best with them. The Mini is a fine amp and it is difficult to get it to sound bad.

You're right about inconsistent CD's SQ. Yet, I'm hoping the digital playback process as well as the USB/DAC streaming can be improved through a better player (i.e., JPLAY) and a better DAC (i.e., JKDAC32).

These may not alter bad recorded material's sound presentation altogether, but should hopefully make them more palatable. Unfortunately, I'm stuck with tipically high-quality musicianship in my selections, where SQ is not necessarilly a correlation.

When the material recording is right, my gear sounds just great as it is.

In my opinion it does help to get the very best front end you can, feed it the cleanest power you can and get it situated as freely from isolation as possible. And then tubes can be selected to be a bit forgiving, which I see as accurate but not super-detailed. That's what's worked for me, that's the path I've been on. I have so many recordings that aren't great, but are listenable and I'm somehow able most of the time to just listen free of the equipment unless I want to focus on the equipment.